The rather small deviation from isotropy observed in the cosmic microwave background (CMB) radiation [1]} makes it plausible that at very early times the universe was indeed anisotropic, therefore prompting the introduction of anisotropic cosmological models to describe the evolution of the universe near the initial singularity [2]}, [3]}. The Bianchi type I model is a natural choice for such a background given that its isotropic limit is the spatially flat Friedmann-Robertson-Lama\(\hat{\i }\) tre-Walker (FRLW) model (see, e.g., [4]}). Indeed, the Bianchi type I model has been recently considered to explain the aforementioned tiny variations in the CMB by a number of researchers [5]}, [6]}, [7]}, [8]}.
